package cn.liontalk.concurrent.shuati;


import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Scanner;

/**
 * 图片整理
 */
public class Main4 {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        while(sc.hasNext()){
            String s = sc.nextLine();
            List<Character> list = new ArrayList<>();
            for (int i = 0; i < s.length(); i++) {
                list.add(s.charAt(i));
            }
            Collections.sort(list);
            StringBuffer sb = new StringBuffer();
            for (Character c : list) {
                sb.append(c);
            }
            System.out.println(sb.toString());
        }

    }


}
